A traditional slip joint can connect two members together. In one example, male splines formed on one member can be slipped into female splines formed on the other member. The splines can be formed by myriad processes that can include cold-forming. Various types of cold-forming processes are commonly referred to as Grob cold-rolling processes or Grobing. Briefly, the Grob processes include forming splines, gear teeth etc. on a tube, shaft or rod by, for example, inserting a mandrel into the member and hammer-forming the member against the mandrel to form a spline end. Other Grobing processes can include cold-rolling and vibration forming.
In an unloaded condition, the members of the slip joint can more longitudinally relative to one another. In a loaded condition, the slip joint can be difficult to decouple. In the loaded condition, however, the slip joint can experience wear due to heat generation. In a forging process, a plastic has been applied to each of the spline ends after forming the splines to reduce the wear between the two members. Additional machining or forming after application of the plastic is then required to re-form the splines. In other examples, the plastic can be injected in between the members of the slip joint to reduce play in the slip joint and reduce wear. The additional machining and/or handling of the injection of the plastic can add cost and complexity to slip joint assembly.